The Fermi Paradox

The idea of where are all the aliens, you mean the Fermi paradox? Yes, exactly. That's probably why it's on the mind. Well, the aliens, the great filter. It's the bomb. I've got another quote from Oppenheimer. In some sort of crude sense, which no vulgarity, no humor, no overstatements can quite extinguish the physicists have known sin. And this is a knowledge which they cannot lose.